Lamp



FIG. 1 is a front perspective view of a lamp, showing my new design;

FIG. 2 is a rear perspective view thereof; and,

FIG. 3 is a top plan view thereof, the broken-line disclosure understood to represent portions of the article in which the claimed design is embodied, but which form no part of the claimed design. 

The ornamental design for a lamp, as shown and described. 